Also, the number of barbs on the side of the needle will effect structural strength (how easy they break). We stock several types of needles:Compact - has 9 barbs Notched - have 1 or 2 barbs per edge (3 or 6 barbs total), and they are at staggered.Crown - are triangular, and have three edges, and a single small barb per edge. (3 barbs)Forked - have a very tiny fork on the tip. Single Barb - needles root the finest and are for advanced rooters only.

For rooting into vinyl, a 38 gauge Crown needle roots about as finely as a 42 gauge Notched needle. This is because Crown needles pull fewer hairs per follicle, because they have fewer barbs on the needle. That is what they are designed to do.